“Usually the common denominator for us losing is getting out-rebounded, so that was a big emphasis,” said Johnson, who had five offensive rebounds.

Arizona (15-2, 3-1 Pac-12) struggled offensively at times without injured guard Gabe York and had a hard time containing Askia Booker after losing to Oregon State in its last game.

The Wildcats pulled out their 31st straight home win by dominating inside.

Arizona outscored the Buffaloes by 16 in the paint and had a 41-26 advantage in rebounds, including 13 on the offensive glass that led to 17 points. Point guard T.J. McConnell, who had eight points and six assists, had seven of those boards, as did Rondae Hollis-Jefferson.

The Wildcats’ 7-foot center Kaleb Tarczewski has just two rebounds in his last 48 minutes — both against Colorado — but had a solid offensive game, scoring 14 points on 5-of-7 shooting. Elliott Pitts provided a scoring lift from the perimeter with York out, hitting 4 of 6 from 3-point range for 12 points.

Ashley was the rebounding catalyst, grabbing four on the offensive glass after getting eight total rebounds the previous three games combined.

“A big reason we won was because of his great efforts on the glass,” Arizona coach Sean Miller said. “If he can be more active on the glass, get us 10-11 rebounds, that’s a lot of good things for us. Get Kaleb rebounding, now you have something.”

The Wildcats did have a hard time slowing Booker.

Colorado’s quick-and-crafty guard had a career-high 30 points on 11-of-17 shooting, including 6 of 9 from 3-point range. That helped the Buffaloes (9-7, 2-2) keep it close early despite playing without Josh Scott (back) and Xavier Johnson (ankle), their second and third-leading scorers.

He just didn’t get much help.

The rest of the Buffaloes combined to hit 10 of 32 shots and no one else scored more than eight, leaving Colorado winless on the road (0-5).

“I thought Booker really played hard tonight,” Colorado coach Tad Boyle said. “But we didn’t play well enough to win. The name of this game was to rebound and we didn’t do that tonight”

Miller was concerned about his team’s defense after a road loss to UNLV.

The Wildcats were solid in wins over Arizona State and Oregon to open the Pac-12 season, but their defensive woes cropped up again in a road loss to unranked Oregon State last week.

Colorado’s leading scorer hit 7 of 9 of shots — all four of his 3-pointers — and had 18 points by halftime.

“My teammates were hyping me … and when I get hot, I feel like nobody can guard me,” Booker said.

Arizona got off to a slow offensive start without York, missing 11 of its first 15 shots. The Wildcats began to find a rhythm, with some help from their non-Booker defense, using an 11-0 run to build a 35-25 halftime lead.

Booker kept hitting shots and his teammates joined him, making 7 of their first 12 in the second half to pull within 47-42.

Colorado: The Buffaloes have played consecutive top-10 teams on the road for a first time since facing No. 2 Kansas and No. 1 Missouri in 1990. … Booker had to leave after rolling his left ankle late in the second half but returned.

Arizona: Johnson had 12 points by halftime. … Tarczewski ended a 43-minute streak without a rebound when he snared one with just over eight minutes left in the second half.

UP NEXT

Colorado plays at Arizona State on Saturday.

Arizona hosts No. 8 Utah on Saturday in the Pac-12’s first matchup between top-10 teams in nearly seven years.